Rack mounted computer servers use self-contained hardware, in the sense that one can plug a rack mounted server into a standard electrical outlet, connect network cables, boot, and have an operational server. Rack mounted servers are often mounted in a computer hardware rack, which is usually 19 inches in width, but some rack mounted servers may also sit in other racks, or sit on a table or another surface instead of being mounted in a rack. Blade mounted servers are not self-contained in the way that rack mounted servers are self-contained. Blade mounted servers are designed to be mounted in a blade enclosure, called a “chassis”, which includes one or more power supplies and networking components. The chassis with one or more blades inserted may be rack mountable.
After power stops flowing to a rack, a chassis, a rack mounted server, a blade mounted server, and/or an individual component of such a server that has data stored in volatile memory, the data may be lost and be unrecoverable. One approach to reduce or prevent loss of data is to replicate the data across multiple servers in a data center, or even across geographically separated data centers. However, a wide variety of other approaches are also possible for saving data despite power loss. Different approaches have different technical characteristics, and any two given approaches are not necessarily related to one another apart from sharing the concept of preserving data against power loss.